Abstract: An improved method which provides for an extended cycle length in catalytic lube dewaxing of residual lube oil feedstocks and easier catalyst regeneration. The method may incorporate catalytically dewaxing a feedstock in a fixed bed reactor with or without product recycle, or a series of reactors with interreactor separation of vapors from liquids. Improved performance is achieved by operating the reactor at a temperature between about 490.degree. and about 620.degree. F., employing a high activity crystalline zeolite catalyst having an alpha value between about 50 and about 900 based on the zeolite and a space velocity sufficiently low to produce a dewaxed effluent of desired pour point and to maintain an average catalyst aging rate of less than about 2.degree. F. per day. This relatively low temperature operation allows catalyst performance to be restored by simple hydrogen reactivation.

Abstract: Disclosed is an improved hydroconversion process for the hydroconversion of heavy hydrocarbon feedstocks containing asphaltenes, metals, and sulfur compounds which process minimizes the production of carbonaceous insoluble solids and catalyst attrition rates. The process is characterized by the use of a catalyst which has about 0.1 to about 0.3 cc/gm of its pore volume in pores having diameters greater than 1,200.ANG. and no more than 0.1 cc/gm of its pore volume in pores having diameters greater than 4,000.ANG..

Abstract: A waxy hydrocarbon feedstock is converted into a high quality lube oil stock of reduced pour point by hydrodewaxing the feedstock in the presence of molecular hydrogen and a hydrodewaxing catalyst under conditions such that the pour point of the feedstock is reduced by selectively converting waxy paraffins into lower molecular weight hydrocarbons. At least a portion of the effluent from the hydrodewaxing zone is then passed to a hydrocracking zone where it is contacted with a hydrocracking catalyst under conditions such that a further reduction in pour point is effected and the overall conversion of components boiling above about 650.degree. F. to components boiling at or below about 650.degree. F. in the hydrodewaxing and hydrocracking steps combined is no more than about 20 percent by volume, preferably no more than about 10 percent by volume.

Abstract: A waxy hydrocarbon feedstock is converted into a product hydrocarbon of reduced normal paraffin content by either dewaxing or hydrodewaxing the feedstock in the presence a dewaxing or hydrodewaxing catalyst under conditions such that the normal paraffin content of the feedstock is reduced by selectively converting waxy paraffins into lower molecular weight hydrocarbons. At least a portion of the effluent from the dewaxing or hydrodewaxing zone is then passed to a hydrocracking zone where it is contacted with a hydrocracking catalyst in the presence of hydrogen under conditions such that a further reduction in the normal paraffin content is effected. When the desired product is a lube oil base stock, the overall conversion of components in the feed boiling above about 650.degree. F. to components boiling at or below about 650.degree. F.

Abstract: A process for the hydrogenolysis of a coal liquid bottom containing benzene-insoluble components and having a boiling point of at least 420.degree. C., which comprises:(a) hydrogenating the coal liquid bottom at a temperature of not higher than 350.degree. C. in the presence of a catalyst comprising an alkali metal and/or an alkaline earth metal and a metal of Group VI A of the Periodic Table to reduce the content of the benzene-insoluble components in the fraction having a boiling point of at least 420.degree. C., to a level of not higher than 10% by weight, and then(b) subjecting the product to hydrogenolysis at a temperature of higher than 350.degree. C. and not higher than 450.degree. C. in the presence of a catalyst comprising a metal of Group VI A of the Periodic Table.

Abstract: A catalytic dewaxing process in which a hydrocarbon feed, usually a lubricant feed, is catalytically dewaxed in at least two catalytic dewaxing stages with an interstage separation of the light ends which are subjected to hydrogenation to saturate the olefins before the hydrotreated product is passed to the second dewaxing stage. The hydrotreated fraction may be the entire fraction below the lube boiling range with a lube feed or a lower boiling portion of it with separated higher boiling portions such as naphtha and distillate by-passing the second dewaxing step.

Abstract: A novel process is disclosed for the production of high boiling jet fuels which comprises contacting a chargestock with an end boiling point of about 750.degree. F. with ZSM-22 under carefully controlled conditions of temperature and pressure and blending the 330.degree. F. plus fraction with a conventional jet fuel in order to obtain a product having acceptable jet fuel properties and having a high boiling range.

Abstract: A multiple single-stage process for the conversion of heavy hydrocarbonaceous charge stock into a lower boiling distillate hydrocarbon product. Fresh charge stock and hydrogen are introduced into a first catalytic reaction zone for substantially 100% conversion of the feed. Hydrocracked product effluent from the first hydrocracking reaction zone which comprises a predetermined distillate fraction is passed with an accucracked effluent from a second catalytic hydrocracking or accucracking reaction zone into a separation zone and separated into various hydrocarbon streams including a light hydrocarbon stream comprising the distillate product, a middle hydrocarbon stream and a heavy hydrocarbon stream. The middle hydrocarbon stream comprising said distillate fraction and hydrogen is introduced into the second catalytic hydrocracking or accucracking reaction zone for conversion into a lower boiling accucracked effluent stream comprising the distillate hydrocarbons boiling in the distillate product range.

Abstract: Temperature is controlled in a hydrogenation reactor without changing the flow rate of feed into the reactor to maintain a pre-determined temperature in the reactor. In one embodiment, the firing rate of a fuel fired furnace for heating feed to the reactor is controlled in response to the temperature sensed in the reactor to maintain a pre-determined temperature. In another embodiment, the flow rate of a quenching stream for cooling feed to the reactor is controlled in response to temperature sensed in the reactor to maintain a pre-determined temperature in the reactor.

Abstract: An improved multistage hydrodewaxing process for hydrodewaxing a hydrocarbon feedstock, such as a heavy or light distillate, is disclosed. A two-phase mixture of a hydrogen-rich gas stream and a liquid hydrocarbon is passed through a series of spaced catalyst beds in a single reactor, reaction vapors containing olefins, are withdrawn at each interspace between beds and replaced with hydrogen-rich saturated gas.

Abstract: A catalyst composition composed of a crystalline aluminosilicate Y zeolite, normally having a silica-to-alumina mole ratio of about 6.2 or above, in combination with a porous, inorganic refractory oxide. The Y zeolite contains ion-exchanged rare earth cations and ion-exchanged Group VIII noble metal cations. The combination of the zeolite and the refractory oxide contains between 4.5 weight percent and about 6.0 weight percent water. Such a catalyst containing the recited amount of water has been found to have consistently high activities when used as a catalyst in a hydrocracking process. The Y zeolites used as part of the catalyst are typically prepared by contacting an ammonium-exchanged Y zeolite with an aqueous solution of ammonium fluorosilicate.

Abstract: A continuous process and system is provided for a petroleum oil in a multi-phase fixed bed catalytic reactor column comprising methods and means for:feeding the oil and a reactant gas at production flow rates above a first bed of porous solid catalyst particles under conversion conditions for cocurrent downward flow therethrough, collecting and withdrawing the treated oil from the first bed and redistributing at least a portion of the treated oil to at least one succeeding catalyst bed while permitting the gaseous phase to flow directly to the succeeding lower catalyst bed, recycling a quantity of treated oil collected below a catalyst bed and reapplying the treated oil at a preceding redistribution zone above the bed from which treated oil is collected, whereby the total of oil production flow rate and recycled treated oil flow rate is maintained at a predetermined minimum sufficient to effect uniform catalyst wetting. This technique is useful for hydrodewaxing of oils over zeolite catalysts.

Abstract: A two-stage hydrotreating process comprises the steps of (1) contacting a liquid hydrocarbon-containing feed stream, which contains nickel, vanadium and Ramsbottom carbon residue, with hydrogen and a solid inorganic refractory material (preferably alumina) for at least partial removal of Ni and V, and then (2) hydrovisbreaking the intermediate product stream from step (1). Preferably, step (2) is carried out in the presence of at least one decomposable compound of a metal, preferably a molybdenum dithiophosphate.

Abstract: Disclosed is an improved multi-stage process for the hydroconversion of heavy hydrocarbon feedstocks containing asphaltenes, metals and sulfur compounds. The process is characterized by the use of a relatively inexpensive demetallation catalyst in a first reaction zone comprising a Group VIB and/or a Group VIII metal deposed on a high macropore volume inorganic support followed by the use of a desulfurization catalyst in a second reaction zone comprising a Group VIB and a Group VIII metal on a high macropore volume inorganic oxide support.

Abstract: Disclosed is an improved ebullated bed process for the hydroconversion of heavy hydrocarbon feedstocks containing asphaltenes, metals, and sulfur compounds. The disclosed process is characterized by the use of a catalyst comprising a relatively small amount of cobalt, i.e., 0.4 to 0.8 wt. % incorporated with a high macropore volume Group VIB metal containing catalyst.

Abstract: A waxy hydrocarbon feedstock is converted into a high quality lube oil stock of reduced pour point by hydrodewaxing the feedstock in the presence of molecular hydrogen and a hydrodewaxing catalyst under conditions such that the pour point of the feedstock is reduced by selectively converting waxy paraffins into lower molecular weight hydrocarbons. At least a portion of the effluent from the hydrodewaxing zone is then passed to a hydrocracking zone where it is contacted with a hydrocracking catalyst under conditions such that a further reduction in pour point is effected and the overall conversion of components boiling above about 650.degree. F. to components boiling at or below about 650.degree. F. in the hydrodewaxing and hydrocracking steps combined is no more than about 20 percent by volume, preferably no more than about 10 percent by volume.

Abstract: An improved method and apparatus are disclosed for hydrodewaxing hydrocarbon feedstock, such as heavy distillate or residual feed. The feedstock is hydrodewaxed in a first step. The resulting first effluent is separated to form a first vapor stream containing olefinic products and a first liquid stream, with a pour point of about 30.degree. to about 100.degree. F. The first liquid stream is then introduced into a second catalytic reaction, where the first liquid stream is hydrodewaxed to a specification pour point less than about 30.degree. F. The method and apparatus may also comprise routing primary products of hydrodewaxing, which contain olefins, as they are removed from the dewaxed first effluent, through an MOGDL unit to convert the olefins to additional high quality lubes. Improvements are due to removal of primary by-products containing olefins which inhibit dewaxing and accelerate catalyst aging and may cause reactor upsets. The addition of the MOGDL unit increases lube yields.

Abstract: A process for hydrocracking a hydrocarbon feedstock having a propensity to form polynuclear aromatic hydrocarbon compounds to suppress fouling the processing unit. The hydrocracking method includes contacting the hydrocarbon feedstock with a crystalline zeolite hydrocracking catalyst, contacting at least a portion of the resulting unconverted hydrocarbon oil containing polynuclear aromatic compounds with an iron catalyst in the presence of hydrogen to hydrogenate and hydrocrack the polynuclear aromatic hydrocarbon compounds, and recycling unconverted hydrocarbon oil having a reduced concentration of polynuclear aromatic compounds to the hydrocracking zone.

Abstract: A hydrocracking process for feedstocks containing high boiling, waxy components uses a number of sequential beds of hydrocracking catalyst based on zeolite beta. The proportion of zeolite beta in the catalyst increases in sequence so that the final bed has the highest zeolite concentration. The dewaxing activity of the zeolite beta-containing catalysts is enhanced by the use of sequential beds in this manner. The pour point of the high boiling fraction is reduced, as well as that of the distillate product, permitting part of the high boiling fraction to be included in the distillate product, thereby increasing the useful distillate yield.

Abstract: High yields of desired distillate oil are obtained by subjecting heavy oil to catalytic conversion with hydrogen at superatmospheric pressure in a temperature staged process, wherein the oil-catalyst slurry is subjected in the initial stage to a temperature in the range of 780.degree.-825.degree. F. (415.degree.-440.degree. C.) and in a subsequent stage to a temperature which is at least 20.degree. F. higher than that employed in the previous stage, preferably in the range of 800.degree.-860.degree. F. (.about.425.degree.-460.degree. C.).

Abstract: Y Zeolites are prepared with rare earth cations and Group VIII metal cations exchanged thereinto, such zeolites being especially useful in hydrocracking catalysts. The zeolites of the invention are prepared by exchanging a sodium Y zeolite with cations of one or more rare earth elements followed by a calcination, an ammonium ion exchange, and a Group VIII metal cation exchange. The resultant zeolite is not only highly active for catalytically promoting hydrocracking reactions but is also, after use in hydrocracking environments resulting in coke deposition, essentially completely regenerable by combustion of the coke.

Abstract: Hydrocarbon feedstocks are dewaxed in a dual catalyst cascade process by passing the waxy feedstock over a crystalline silicate zeolite catalyst having a Constraint Index between 2 and 12, and then over a different crystalline silicate zeolite catalyst having a Constraint Index no less than 2.

Abstract: Catalytic dewaxing of hydrocarbon oils is effected with intermediate hydrotreating. A continuous multi-bed technique employs alternating beds of dewaxing and hydrogenation catalysts to improve process performance, whereby partially dewaxed effluent is treated to decrease coke deposits.

Abstract: Heavy crudes or vacuum residues are treated in a thermal hydroconversion process in the presence of a metal catalyst from Groups IVb, Vb, VIb, VIIb and VIII of the Periodic Table of Elements and water. Fresh catalyst is introduced into the process as a soluble, metallic catalyst precursor which is then decomposed while feedstock admixed with water is preheated to a temperature of at least about 230.degree. C. but no more than about 420.degree. C.

Abstract: An improved process for catalytic desulfurization of petroleum residua feedstocks to provide at least about 75% desulfurization of the liquid product while achieving low catalyst deactivation and increased catalyst age. In the process which uses an ebullated catalyst bed reactor, the reaction conditions are usually maintained at 790.degree.-860.degree. F. temperature, 1000-1800 psig hydrogen partial pressure, and 0.2-2.0 Vf/hr/Vr space velocity. To control carbon and metals deposition on the catalyst, used catalyst is withdrawn from the reactor, a minor portion of the catalyst is discarded to control metals deposition and maintain catalyst activity, and the remaining catalyst is regenerated to remove carbon by carbon burnoff and returned to the reactor for further use. If desired, the regenerated catalyst can be presulfided before returning it to the reactor. Following phase separation and distillation steps, the desulfurized hydrocarbon liquid products are withdrawn from the process.

Abstract: The invention relates to a process for catalytically hydrodewaxing hydrocarbon feedstocks over zeolite ZSM-22 to produce high yields of low pour, high viscosity index hydrocracked lubricating oil stock.

Abstract: A process for the production of transportation fuels from heavy hydrocarbonaceous feedstock is provided comprising a two-stage, close-coupled process, wherein the first stage comprises a hydrothermal zone into which is introduced a mixture comprising the feedstock, dispersed demetalizing contact particles having coke-suppressing activity, and hydrogen; and the second, close-coupled stage comprises a hydrocatalytic zone into which substantially all the effluent from the first stage is directly passed and processed under hydrocatalytic conditions.

Abstract: A process for the production of transportation fuels from heavy hydrocarbonaceous feedstock is provided comprising a two-stage, close-coupled process, wherein the first stage comprises a hydrothermal zone into which is introduced a mixture comprising a feedstock and dispersed activated or presulfided red mud having demetalizing and coke-suppressing activity, and hydrogen; and the second, close-coupled stage comprises a hydrocatalytic zone into which substantially all the effluent from the first stage is directly passed and processed under hydrocatalytic conditions.

Abstract: A process for the production of transportation fuels from heavy hydrocarbonaceous feedstock is provided comprising a two-stage, close-coupled process, wherein the first stage comprises a hydrothermal zone into which is introduced a mixture comprising a feedstock and red mud having coke-suppressing and demetalizing activity, and hydrogen; and the second, close-coupled stage comprises a hydrocatalytic zone into which substantially all the effluent from the first stage is directly passed and processed under hydrocracking conditions.

Abstract: A process for the production of transportation fuels from heavy hydrocarbonaceous feedstock is provided comprising a two-stage, close-coupled process, wherein the first stage comprises a hydrothermal zone into which is introduced a mixture comprising a feedstock and metals-impregnated red mud having coke-suppressing and demetalizing activity, and hydrogen; and the second, close-coupled stage comprises a hydrocatalytic zone into which substantially all the effluent from the first stage is directly passed and processed under hydrocatalytic conditions. The preferred metals for impregnation include transition metals, in particular, nickel and molybdenum.

Abstract: A process for dewaxing a hydrocarbon feedstock with a relatively high pour point and containing normal and slightly branched paraffins by subjecting said feed to catalytic dewaxing over a noble metal promoted zeolite beta catalyst followed by dewaxing with a base metal promoted zeolite beta catalyst. The feed may be hydrotreated before dewaxing.

Abstract: Lubricating oil stocks produced by methods such as catalytic dewaxing or hydrocracking, comprising hydroprocesses, are stabilized against oxidation by the addition of hydrogen sulfide to the hydroprocessing hydrogen-containing feed using hydroprocess effluent as a source of said hydrogen-containing feed. The H.sub.2 S present in the hydrogen-containing feed saturates olefins that contribute to oxidation instability and restores antioxidant sulfur compounds such as thiols to the lube stock.

Abstract: A process for high hydroconversion of petroleum residua containing at least about 25 V % material boiling above 975.degree. F. to produce lower boiling hydrocarbon liquid products and avoid undesirable precipitation of asphaltene compounds. In the process, the feedstock is at least about 80 percent catalytically hydroconverted to material boiling below 975.degree. F. and containing a mixture of gas and liquid fractions, after which the gas fraction is removed while maintaining the resulting liquid fractions temperature above about 730.degree. F. to avoid precipitation of asphaltene compounds which causes operations difficulties in the downstream equipment. Alternatively, the pressure-reduced liquid fraction can be stripped of material boiling below about 650.degree. F. before cooling the liquid to a temperature below about 730.degree. F. to prevent such precipitation of asphaltene compounds in the downstream equipment.

Abstract: A process for conversion of an asphaltenes-containing heavy oil or heavy oil fraction to lighter fractions comprises 3 steps of: catalytic hydrodemetallation, hydrovisbreaking and catalytic hydrodesulfuration.

Abstract: An asphaltene-containing heavy oil or heavy oil fraction is converted to lighter fractions in a process comprising three steps: a hydrovisbreaking, a catalytic hydrodemetallation and catalytic hydrodesulfuration.

Abstract: A process for the production of jet fuels, diesel fuels, multi-purpose fuels meeting the specifications for both high grade jet fuels and diesel fuels, and high quality blending components useful for the production of such fuels; and the compositions produced thereby. In accordance with the process, a multi-reactor system, inclusive of a first reactor and a second reactor are connected through a first distillation column which separates the product of the first reactor into two or more fractions to provide a heavy feed fraction which is charged to the second reactor, wherein the heavy feed is hydroselectively cracked. The product from the second reactor is fractionated to produce high quality jet and diesel fuels, multi-purpose jet and diesel fuels, or provide a major blending component for the production of such fuels, or fuel components.

Abstract: A process is disclosed for converting a non-distillable residue of a mixed-base or paraffin-base crude hydrocarbon oil to a distillable precursor for motor fuels and/or petrochemical products which comprises donor solvent hydrovisbreaking said residue in a hydrovisbreaking zone in the presence of a circulated hydrogen donor solvent at a temperature in the range of 380.degree. to 480.degree. C.

Abstract: A process for the hydrotreatment of a heavy hydrocarbon fraction containing sulfur and metal impurities comprises at least two steps: a first step using a catalyst comprising a low proportion of at least one metal of groups V, VI and VIII, said catalyst being in the form of a plurality of juxtaposed agglomerates each formed of a plurality of acicular plates, the plates of each agglomerate being generally oriented radially with respect to one another and with respect to the center of the agglomerate, the carrier of this catalyst being preferably inert; and a second step using a catalyst which could be of the same type but with a higher proportion of metals. This process is useful for the conversion of crude oils, straight run hydrocarbon residues, deasphalted oils, asphalts dissolved in aromatic distillates and coal hydrogenates.

Abstract: A process for high hydroconversion of petroleum residua containing at least about 25 V % material boiling above 1000.degree. F. to produce lower boiling hydrocarbon liquid products and avoid undesirable precipitation of asphaltene compounds. In the process, the feedstock is at least about 50 percent catalytically hydroconverted to material boiling below 975.degree. F. and containing a mixture of gas and liquid fractions, after which the gas fraction is removed and the resulting liquid fractions is pressure-reduced and quenched to a temperature below about 775.degree. F. To avoid precipitation of asphaltene compounds which causes operational difficulties in the downstream equipment, the quench liquid used should have an API gravity not more than about 22.degree. API higher than the API gravity of the first pressure-reduced liquid fraction.

Abstract: A process for high hydroconversion of heavy hydrocarbon liquid feedstocks such as petroleum residua containing at least about 50 V % material boiling above 975.degree. F. to produce lower boiling hydrocarbon liquid and gas products, wherein heavy RCR materials and metals compounds are removed in-situ from the reactor effluent liquid by solvent vapor extraction using a process-derived solvent vapor at supercritical conditions. In the process, the feedstock is catalytically hydroconverted at 780.degree.-860.degree. F. temperature, and the resulting liquid fraction is contacted with a process-derived solvent vapor fraction having a normal boiling range of 250.degree.-400.degree. F. and heated to supercritical temperature to dissolve and extract substantially all the hydrocarbon liquid fractions, and separate heavy RCR materials and the metals compounds contained therein.

Abstract: A process for converting, into lighter viscosity products, heavy fractions from petroleum or other hydrocarbon refining, e.g. asphaltenes; catalysts especially suitable therefor and a process for this conversion have been disclosed; by further upgrading, the obtained products can be usefully employed as fuels and the like.

Abstract: A heavy hydrocarbon oil comprising constituents boiling above 1050.degree. F. is upgraded by a combination visbreaking or hydrovisbreaking and hydrorefining process in which at least a portion of the hydrorefined bottoms fraction is recycled to the visbreaking zone. The hydrorefining zone is operated at conditions to convert at least a portion of the 1050.degree. F..sup.+ constituents to lower boiling hydrocarbons.

Abstract: A method for controlling the temperature and composition of a vapor feedstream into a second reactor connected in series flow arrangement with a first reactor. The effluent stream from the first reactor containing vapor and liquid fractions is first cooled against a vapor stream and then further cooled against a suitable external fluid, then is phase separated to provide vapor and liquid fractions. The separated vapor fraction is reheated against the first reactor effluent stream and passed at an intermediate temperature into the second reactor. The first reactor is preferably an ebullated bed type catalytic reactor and the second reactor is preferably a fixed bed type catalytic reactor which is operated at an inlet temperature 20.degree.-200.degree. F. lower than the first reactor effluent stream temperature.

Abstract: A two-stage catalytic hydroconversion process for heavy hydrocarbon feedstocks usually containing fine particulate solids to produce lower boiling hydrocarbon liquid and gas products. The feedstock is fed into a first stage ebullated bed reactor containing fine sized catalyst and operated at moderate reaction conditions for hydroconversion to produce hydrocarbon gas and liquid fractions, from which a low boiling liquid fraction is separated and withdrawn as a product. The remaining gas and heavier liquid fractions are recombined and fed to a second stage ebullated bed reactor containing larger size catalyst for further hydroconversion reactions at less severe conditions to produce lower boiling hydrocarbon liquid fractions. Following product distillation steps, liquid product fractions are withdrawn and a portion of vacuum bottoms material is recycled to the second stage reactor to provide increased hydroconversion and improved yields of the light hydrocarbon liquid product.

Abstract: A process for upgrading a heavy hydrocarbonaceous oil is provided in which the heavy oil is hydrorefined in the presence of a hydrorefining catalyst at conditions to convert a portion of the heavy constituents of the oil, followed by cracking the hydrorefined oil in the presence of the hydrogen donor diluent. The hydrorefining and cracking stages are conducted at a relatively low hydrogen partial pressure while obtaining a high level of conversion of the heavy constituents of the oil.

Abstract: A multistage hydrocracking or hydrotreating process wherein a two-phase reaction mixture of a hydrogen rich gas stream and liquid hydrocarbon is passed through a series of spaced catalyst beds and reaction vapors are withdrawn at each interspace between beds and replaced with hydrogen. Such withdrawal and replacement reduces the partial pressure of NH.sub.3 and/or H.sub.2 S in the reaction mixture entering the bed succeeding each interspace, thereby increasing the reaction rate between hydrogen and the liquid hydrocarbon.

Abstract: Waxy shale oil feeds containing organonitrogen and/or organosulfur components are contacted with a catalyst comprising a Group VIB metal component on a support containing silicalite and a porous refractory oxide under conditions of elevated temperature and pressure and in the presence of hydrogen so as to simultaneously reduce its pour point and its organosulfur and/or organonitrogen content.

Abstract: Resids are hydrocracked at low pressure (600 psig and 825.degree. F.) in a solvent, while being demetalated, desulfurized, and decarbonized, by passing the solution through a dual-bed catalytic system having a large-pore catalyst as the first bed and a small-pore as the second bed. The solvent is preferably process generated and recycled, boiling at about 400.degree.-700.degree. F.

Abstract: Zeolite catalysts having a low constraint index maximize conversion of hydrotreated shale oil primarily to the preferred 400-600.degree. F. boiling range distillate.

Abstract: .[.In a hydrogenation operation employing an ebullated catalytic bed, recycle is recovered from the hydrogenated product with at least 25%, by volume, of the recycle boiling above 950.degree. F. The recycle is cooled to a temperature of from 350.degree. to 600.degree. F. to separate coke precursors, prior to recycle to the hydrogenation. Higher conversion levels can be achieved by effecting recycle in such manner..]..Iadd.Disclosed is a hydrogenation process using at least one fluidized catalytic stage and a recycle material of heavy hydrogenated effluent. The heavy effluent material is cooled to a temperature within 350.degree.-600.degree. F. to separate toluene and heptane insoluble coke precursors prior to recycle. This separation may be enhanced by the use of centrifugation, filtration or a bed of particulate material (e.g. calcined coke). .Iaddend.